Rotary damper and image forming apparatus

摘要

A plurality of first viscoelastic bodies are disposed in insertion holes of a first rotary member. A plurality of second viscoelastic bodies are disposed in guide holes of a second rotary member. Each of the first and the second viscoelastic bodies has an elastic coefficient changing in accordance with aging due to use. A guide member moves a contact member along the insertion hole and the guide hole. The contact member applies a compressive load to the first viscoelastic body. The aging of the second viscoelastic body due to the compressive load applied thereto moves a position of the first viscoelastic body where the compressive load is received from the contact member toward a farther side from a rotational shaft side.

主权项

1. A rotary damper comprising:
a first rotator configured to rotate about a rotational shaft; a second rotator configured to rotate about the rotational shaft; at least one first viscoelastic body disposed between the first rotator and the second rotator; and a contact member disposed between the first rotator and the second rotator, and configured to apply a compressive load in a rotation direction about the rotational shaft to the at least one first viscoelastic body while being in contact with the at least one first viscoelastic body so that a torque is transmitted between the first rotator and the second rotator, wherein a contact position of the contact member to the at least one first viscoelastic body moves in a radial direction of the rotational shaft.